The Book of Jihad and Expedition (Kitab Al-Jihad wa'l-Siyar)
Muslim :: Book 19 : Hadith 4292
Ibn 'Aun reported: I wrote to Nafi' inquiring from him whether it was necessary to extend (to the disbelievers) an invitation to accept (Islam) before m". ing them in fight. He wrote (in reply) to me that it was necessary in the early days of Islam. The Messenger of Allah (may peace be upon him) made a raid upon Banu Mustaliq while they were unaware and their cattle were having a drink at the water. He killed those who fought and imprisoned others. On that very day, he captured Juwairiya bint al-Harith. Nafi' said that this tradition was related to him by Abdullah b. Umar who (himself) was among the raiding troops.